Embedded software test tools are a lot of. Just Parasoft C/C++ test, LDRA testbed, CodeTest, and ScopeTools.
To develop a serial driver is much easy. You can write it based on the original serial driver of VxWorks.
Right now, Tornado II is too old. Most people use the Tornado2.2.x. Trial version is just the simulation and commercial version is for some CPU type, just like PowerPC and ARM, etc.
How much? Hm......, maybe a basic version of Tornado2.2 will cost 30,000$.
Good Lucky.